Anthraquinone dye.



nsrrn screens PATNT FKJCE,

PAUL THOMASCHEWSKI, OF ELBE'RFELD, GERMANY, ASSIGNOR TO FARBENFABRIKEN OF ELBERFELD (10., OF NEW YORK, N. Y., A

CORPORATION OF NEW YORK.

ANTHRAQUiNONE DYE.

Specification of Letters Patent.

Patented Oct. 10, 1905.

Application filed June 10, 1905. Serial No. 264,698.

[ (all whom it may concern.-

Be it known that 1, PAUL THOMASCHEWSKI, doctor of philosophy, chemist, residing at Elberfeld, Germany, (assignor to the FARBEN- FABRIKEN OF ELBERFELD 00., of New Yorln) have invented a new and useful Improvement in Anthraquinone Dyes; and I hereby declare the following to be a clear and exact description of my invention.

My invention relates to the manufacture of a new dyestufi, being a hydroazin derivative of the anthracene series.

The process for producing this coloring matter consists in heating the 1-oxy-3-bromo-4- 5 amidoanthraquinone (obtainable by the action of bromin on paraamido-oxyanthraquinone) with cupric chlorid in the presence of a suit-'- able dissolving or diluting agent and preferably with the addition of a product having a weak alkaline reaction, such as sodium acetate or the like. The reaction proceeds most probably according to the following equation:

In carrying out the process practically I can proceed as follows, the parts being by weight: A mixture of ten parts of l-oxy-3-bromo-4ramidoanthraquinone, one hundred parts of naphthalene, twelve par Us of pulverized anhydrous sodium acetate, and one-fourth part of cupric chlorid (CuCh) is heated to boiling for about five hours while stirring. The crystalline precipitate thus obtained is filtered off, washed with alcohol and then with hot water.

My new coloring-matter thus obtained crystailizes from quinoiin in the shape of blue needles having a cupreous luster. It is soluble in hot quinolin with a bluish-green color and soluble in concentrated sulfuric acid with an olive-green color. d rosultite and caustic-soda lye it is transformed into its hydro compound, the blue alkaline solution of which has the properties of a vat suitable for dyeing and printing unmordanted cotton pure greenish blue fast shades.

Having now described my invention and in what manner the same is to be performed,

what I claim as new, and desire to secure by Letters Patent, is

The herein-described new dyestufi being a hydroazin derivative of the anthracene series obtainable by heating 1-oxy-3-bromo-4-amidoanthraquinone with cupric chlorid and a suitable diluting agent, which dyestuif represents blue needles of a cupreous luster soluble in hot quinolin with a bluish-green and solua ble in concentrated sulfuric acid with an olivegreen color; being transformed into a hydro compound by suitable reduction with hydrosuliite and caustic-soda lye, the blue alkaline solution thus obtained exhibiting the typical properties of a vat which dyes unmordanted cotton pure greenishblue shades, substantially as hereinbefore described.

In testimony whereof I have signed my name in the presence of two subscribing witnesses.

PAUL 'lHOMASOHEWSKI.

Upon'treatment with hy- 

